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（1 青海大學(xué)土木工程學(xué)院， 西寧 810016； 2 青海省建筑建材科學(xué)研究院， 西寧 810008）
［摘要］由于青海地處高原且地下鹵水環(huán)境對軌道梁的壽命影響不容忽視，展開對軌道梁在鹵水腐蝕下的疲勞試驗研究十分必要。通過對4種不同配合比的混凝土梁在不同腐蝕條件下的疲勞試驗，研究了混凝土梁在水環(huán)境及鹵水環(huán)境下的鋼筋銹蝕率、鋼筋力學(xué)性能變化、氯離子含量、梁疲勞壽命及力學(xué)行為失效機理等，并繪制了不同模型的應(yīng)力比-疲勞壽命（S-N）曲線，擬合出了S-N曲線方程。試驗結(jié)果表明：鹵水能加速鋼筋銹蝕并影響混凝土梁的疲勞壽命，且在低銹蝕下能略微提升混凝土梁的疲勞壽命；疲勞破壞包括初裂、裂縫的開展、損傷的積累三個階段，且箍筋具有一定的抗裂性；強度越高的高性能混凝土梁在相同腐蝕條件下疲勞壽命越長；低銹蝕率的混凝土梁的疲勞壽命很大程度上由其應(yīng)力比決定。研究結(jié)果可為低銹蝕率鋼筋混凝土梁疲勞性能評估提供理論依據(jù)。
［關(guān)鍵詞］高性能混凝土梁； 鹵水； 疲勞壽命； S-N曲線方程
中圖分類號：TU375-1文獻標(biāo)識碼：A文章編號：1002-848X(2018)06-0012-05
Study on fatigue behavior of high performance concrete beams under brine corrosion
Zhao Xuan1, Liu Lianxin1, Huang Lei1, Liu Chengkui2, Wang Wei1
(1 School of Civil Engineering, Qinghai University, Xining 810016, China; 2 Qinghai Province Science Research Institute of Building & Construction Material, Xining 810008, China)
Abstract:Qinghai is located in the plateau, and the influence of the underground brine environment on the life of the rail beam cannot be ignored, so it is necessary to carry out fatigue test study on track beam under brine corrosion. The fatigue tests of concrete beams with 4 different mix ratios under different corrosion conditions were carried out. The corrosion rate of steel bars, the mechanical properties of concrete, the content of chloride ion, the fatigue life of beams and the failure mechanism of mechanical behavior of concrete beams under water environment and brine environment were studied. The stress ratio-fatigue life (S-N) curves of different models were drawn, and the S-N curve equation were fitted. The experimental results show that the brine can accelerate the corrosion of steel bars and affect the fatigue life of concrete beams, and can slightly increase the fatigue life of concrete beams under low corrosion; fatigue failure includes three stages of incipient crack, crack development and damage accumulation, and stirrups have certain crack resistance; high performance concrete beam with higher concrete intensity has higher fatigue life under the same condition of corrosion; fatigue life of concrete beams with low corrosion rate is decided to a large extent by its stress ratio. The research results provide a theoretical basis for the evaluation of fatigue performance of reinforced concrete beams with low corrosion rate.
Keywords:high performance concrete beam; brine; fatigue life; S-N curve equation
*西寧軌道交通工程混凝土結(jié)構(gòu)關(guān)鍵技術(shù)研究及示范項目（2013-G-Q06A）。
作者簡介：趙宣，碩士研究生，Email：1103250228@qq.com。
